The present invention relates to a flexible conduit assembly for the conduction of fluids and more particularly the invention relates to a tube system with an outer, corrugated tube and an inner, also flexible tube whereby the space between the tubes is also available for the conduction of fluid.
Fluids are often to be conducted through a flexible tubing. It was observed, however, that corrugated tubes may undergo longitudinal oscillations particularly for velocities of the fluid above some value. That wave depends on the corrugation contour. Such oscillations may readily lead to damage of the tube.
A known tube system (German printed patent application 1,935,191) is constructed from a helically corrugated, outer tube having connecting pieces at both ends, and a flexible tube or sleeve is situated on the inside of the corrugated tube and in such a manner that the inwardly oriented corrugation crests of the outer tube engage the outer surface of the inner tube. The inner tube serves as conduit proper but some of the flow is diverted into the helical duct as defined by the outwardly oriented corrugation crests of the outer tube and the inner tube. This particular secondary flow path is a continuous one, without exhibiting any pockets or the like in which precipitates or other additives could accumulate. Also, this helical secondary flow path envelopes the inner tube in a uniform manner and provides for thermal as well as noise insulation. However, it must be observed that flow dynamically the helical conduit is only of limited usefulness; such an assembly cannot be made too long, as otherwise insufficient amounts of fluid will be driven through that helical channel, and the entire flow therethrough with more and more stagnate.